Ox the Absence of Isoagglutinins in Mice 



95 



small amounts of blood taken with a pipette and added to about 

 a c.c of a 0.7 per cent, salt solution. Based on the light pink color, 

 cell suspensions of a suitable concentration were obtained. This 

 method was used because the main problem necessitated a pro- 

 cedure that did not require killing the mouse to be tested. Each 

 test was made by microscopic examination of a hanging drop of 

 equal quantities of cell suspension and serum; the observations 

 were made within an hour. 



From the various races of mice forty-eight sera were made, 

 and a total of 300 samples were tested; the total number of differ- 

 ent combinations of cells and sera was 1,180. Of these combina- 

 tions only two showed any agglutination. These two cases were 

 combinations of cells from two wild mice and serum from a 

 Storrs-Little pink-eyed black. Repeated tests with cells from the 

 same mice and serum from mice related to the one that gave the 

 first serum failed to give further agglutinations. 



Since one m'ouse yields such a small amount of serum, at best 

 2 c.c, it was thought that some other serum, obtainable in larger 

 quantities might have advantages in testing for differences in 

 the blood of different strains of mice. 



To this end four guinea-pig sera were used in making 180 

 tests; four sheep sera were used in making 136 tests, and nine 

 white rat sera were used in making 276 tests. In every case the 

 guinea-pig and sheep sera showed unquestionable agglutination, 

 and in no case did the rat sera show any signs of agglutination, 

 although the whole range of mouse races was tested with each 

 of the sera. 



These results appear to be conclusively negative from the 

 standpoint of finding blood groups in mice that could be utilized 

 in a genetic study; from the standpoint of the agglutinations be- 

 tween different species, it appears that guinea-pig and sheep dif- 

 fer from rats in the reactions of their sera to mouse cells. 



